| 摘要 |
PURPOSE:To obtain a focus detector of high distance measurement precision by constituting a part of a photodetecting means with a wedge prism consisting of a viscoelastic body and changing the wedge angle of this wedge prism to guide a reflected luminous flux to a certain position on the surface of a photodetector. CONSTITUTION:The luminous flux from a light emitting element 2 is projected to the object side through a part of a photographing system 1, and the reflected luminous flux from the object side is guided to a photodetector 5 through a photodetecting lens 3 and a wedge prism 4 consisting of a transmission viscoeladtic body which are arranged near the photographing system 1. The wedge angle of this wedge prism 4 is changed to lead the reflected luminous flux to a certain position on the surface of the photodetector 5, and focus detection of the photographing system 1 is performed in accordance with the wedge angle at this time. |
